Foundation

ABSTRACT

A cosmetic composition is provided comprising
         (a) metal oxide particles; and   (b) greater than 1.7% by weight of the cosmetic composition of cross-linked organopolysiloxane elastomer,
 
wherein organo-functionalised silicone fibrils are bonded to and extend away from the surface of the metal oxide particles.

FIELD OF THE INVENTION

The present application concerns cosmetic compositions, especiallycosmetic foundation compositions.

BACKGROUND OF THE INVENTION

It is known to include fatty or oleophilic materials, includingsilicones, in cosmetic products to provide occlusive(moisture-retention) properties, improved feel properties, as solventsand for other reasons. It is also known to include metal oxide particlebenefit agents in cosmetic compositions—depending on the type of oxide,the particle size and/or configuration, agents may, for example, providepigmentary and/or sunscreening benefits. In order to marry the benefitsof both types of component, it is a natural step to consider includingboth types of component in a single composition. This presentsdifficulties, however, because metal oxide particles generally do notreadily disperse in a hydrophobic matrix. To overcome this difficulty,it is known to stabilise metal oxide particles within an oleophilicphase by adding emulsifying agents to a composition.

Emulsifiers in low dielectric constant media may use steric effects toprovide stabilisation and prevent flocculation. To be more precise, theemulsifier coats the free surface of the particle with hydrophilic tailsand extends oleophilic chain into the medium and the chain acts toprevent agglomeration by osmotic effects: as two particles approach oneanother, the chains overlap and cause a temporary increase in polymerconcentration. This increase causes an osmotic stress that forces fluidbetween the particles, thereby causing them to separate.

The addition of free emulsifier to a composition may, however, not besufficient to ensure a good particle dispersion throughout the lifecycle of the product. If the concentration of emulsifier is too low thenthe osmotic stress will be correspondingly low and, as two particlesapproach one another, the emulsifier may bridge the particles actuallypromoting agglomeration. If, on the other hand, the concentration ofemulsifier is too high, then the osmotic stress behaviour may bereversed leading to depletion flocculation. In this scenario, theconcentration of free emulsifier may be so high that, as particlesapproach one another, free emulsifier may be forced out from betweenthem. The concentration difference may create an osmotic stress thatdraws fluid out of the space between the particles thereby promotingagglomeration.

An ideal level of emulsifier exists for any system but small changes inthat system may cause the the amount of emulsifier to move away from theoptimum, thereby leading to the above-described problems. Especially inthe case of a product that is required to dry down in use, it is almostimpossible to achieve an ideal level of emulsifier at all time points,because, during the drying process, the emulsifier concentrationcontinually increases. In other words, the use of non-bonded coating onthe surface of the particle means that for any system the emulsifierconcentration must be sub-optimal at some stage in its life cycle.

To overcome the disadvantages of non-bonded emulsifier coatings, use ofa coating which is bonded to the surface of a particle may be employed.Bonding may prevent the emulsifier bridging and, since the there is nofree emulsifier in the solution, depletion flocculation may be avoided.In addition, since it is no longer necessary to prevent diffusion ofemulsifier away from the surface, there is no requirement to control thehydrophilic/lipophilic balance (HLB) of the emulsifier. As a result, themolecules in a bonded coating may have longer tails than non-bondedemulsifiers, which, in turn, may increase the steric stabilisationeffect.

It is known to formulate compositions comprising metal oxide particleswhich have been coated with bonded emulsifier to provide stericstabilisation. Such formulations are disclosed in the article entitled“Development of Novel Silicones for Powder Surface Treatment” by MasaneoKamei in the Fragrance Journal, p. 81-85, 2002-6. The cosmeticcompositions disclosed in that article are difficult to apply to skin,however, which may result in the benefit achieved by the metal oxideparticle benefit agent being less even than it should be.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, a cosmetic composition isprovided comprising:

-   -   (a) metal oxide particles; and    -   (b) greater than 1.7% by weight of the cosmetic composition of        cross-linked organopolysiloxane elastomer,        wherein organo-functionalised silicone fibrils are bonded to and        extend away from the surface of the metal oxide particles.

As used herein, the term “bond” includes, but is not limited to,chemical bonds, such as chemisorption and covalent bonds. The term“bonded” is to be interpreted accordingly.

According to a second aspect of the invention, cosmetic foundationcompositions are provided comprising cosmetic compositions according tothe first aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

All weights, measurements and concentrations herein are measured at 25°C. on the composition in its entirety, unless otherwise specified.

As used herein in relation to metal oxide sunscreen particles, allweights of doping or coating materials are given as percentages of theweight of the underlying metal oxide particle which is thus doped orcoated. This definition applies even when the doping or coating materialis, itself, a metal oxide. Thus, if the particles weigh x grammes andthe coating or doping material weighs y grammes, the percentage weightof the coating or doping material is y/x*100.

As used herein in relation to the cosmetic composition, the percentageweight of the metal oxide sunscreen particles is the combined weight ofthe underlying metal oxide particle and any doping or coating divided bythe weight of the entire cosmetic composition. Thus, if the particlesweigh x grammes, the coating or doping material weighs y grammes and theentire cosmetic composition (including the coated or doped metal oxideparticles) weighs z grammes, then the percentage weight of the metaloxide particle is (x+y)/z*100.

Unless otherwise indicated, all percentages of compositions referred toherein are weight percentages of the total composition (i.e. the sum ofall components present) and all ratios are weight ratios.

Unless otherwise indicated, all polymer molecular weights are numberaverage molecular weights.

Reference herein to the percentage weight of cross-linkedorganopolysiloxane elastomer in a composition is a reference to thepercentage weight of solid organopolysiloxane elastomer in thatcomposition, not to the percentage weight of solid organopolysiloxaneelastomer plus solvent in the composition. This is stated for theavoidance of doubt, since commercially available organopolysiloxaneelastomers are often sold in combination with a solvent.

Unless otherwise indicated, the content of all literature sourcesreferred to within this text are incorporated herein in full byreference.

Except where specific examples of actual measured values are presented,numerical values referred to herein should be considered to be qualifiedby the word “about”.

Metal oxide primary particles in the nano- and micrometer size rangehave high surface areas per unit volume and are correspondingly reactiveleading to their agglomeration to form secondary particles. Thisagglomeration is inevitable and, up to a point, may not beundesirable—minute, nanometer-size particles do not scatter light,making them less suitable as UV-A sunscreens. If the secondary particlesize is unchecked, however, then the particles generated may not havethe required properties and the composition may not provide an evenbenefit in use. In addition, particularly in the case of sunscreens,excessive agglomeration may alter or significantly reduce the benefitobtained: it is believed that the primary particle size drives theoverall surface area of the secondary particles, with smaller primaryparticles generally giving rise to secondary particles of greatersurface area. Secondary particle surface area, in turn, is believed todrive absorption of UV-B radiation—the larger the secondary particlesurface area, the greater the degree of UV-B absorption. Secondaryparticle size, on the other hand, is considered to drive scattering ofUV-A radiation, with larger particles reflecting more. Without wishingto be bound by theory, it is believed that agglomeration of secondaryparticles may reduce both UV-B absorption and UV-A scattering, therebysignificantly affecting the sunscreening benefit: agglomeration ofsecondary particles drives down overall secondary particle surface area,thereby reducing the degree of UV-B absorption; in addition, whilst UV-Areflection does increase with secondary particle size, the overallnumber of secondary particles drops with increasing agglomeration,thereby reducing UV-A reflection too.

In order to reduce or prevent agglomeration of secondary particles, themetal oxide particles are provided with a coating oforgano-functionalised silicone fibrils, which fibrils are bonded to andextend away from the surface of the metal oxide particles into thecarrier medium. As already discussed, it is believed that, as coatedmetal oxide particles approach one another, their fibrils may becomeenmeshed. The resulting high concentration of organo-functionalisedsiloxane polymer in the region where that enmeshing is occurringgenerates a high osmotic pressure causing carrier fluid to flow inbetween the adjacent particles and force them apart.

The fibrils may advantageously be attached by treating the metal oxideparticles with an organo-functionalised silicone polymer comprising areactive moiety selected from the group consisting of amino, imino,halogen, hydroxyl, and alkoxyl such that the organo-functionalisedsilicone polymer becomes adsorbed to the surface of the metal oxidepolymer.

Advantageously, the organo-functionalised silicone polymer comprisesfrom 5 to 100, preferably from 25 to 50 silicone repeating units.Polymers of this size project into and may flow freely in the carriermedium, thereby avoiding agglomeration further. As used herein, a“silicone repeating unit” or “silicone unit” means

where each of X and Y is, independently, an alkyl group or anyfunctional group.

Preferably, the organo-functionalised silicone polymer has a ratio(Mw/Mn) of weight-average molecular weight (Mw) to number-averagemolecular weight (Mn) from 1.0 to 1.3. Without wishing to be bound bytheory, it is believed to be important that the surface coating be aseven as possible to maximise the osmotic pressure and also to avoidbridging flocculation by comparatively longer polymer chains.

The organo-functionalised silicone polymer may be a linearorganofunctionalised silicone polymer. In this case, it is preferred tolocate the reactive moiety at one end of its molecular chain.

Alternatively, the organo-functionalised silicone polymer may be abranched chain organofunctionalised silicone polymer. In this case, thereactive moiety is preferably located on a side chain. Advantageously,the side chain on which the reactive moiety is found is located withinfive silicone repeating units, preferably within three siliconerepeating units of one end of the silicone backbone.

To manufacture the coated metal oxide particles, organo-functionalisedsilicone polymer, as specified above, an organic solvent which dissolvessaid organo-functionalised silicone polymer, and metal oxide are mixed,then dried by heating. The organo-functionalised silicone polymer shouldbe used in an amount from 0.1 wt % to 30 wt %, preferably from 1 wt % to15 wt %, more preferably from 2 wt % to 8 wt % of the metal oxideparticles to be treated, depending on its particle diameter and specificsurface area.

An appropriate organic solvent should be selected in consideration ofits flash point and ignition point, and the surface activity and heatstability of the metal oxide particles for surface treatment. Preferredexamples of the organic solvent include ethers, ketones, halogenatedhydrocarbons, aliphatic hydrocarbons, and alcohols and mixture thereofwith other solvents such as water. The organic solvent should be used inan amount of 1-50 wt % to the metal oxide particles.

The mixing of the organo-functionalised silicone polymer, organicsolvent, and metal oxide particles may be accomplished by putting themtogether into an ordinary mixer, or by spraying theorgano-functionalised silicone polymer onto a mixture of the organicsolvent and metal oxide particles. The heating of the mixture should becarried out in an adequate manner in consideration of the heatresistance of the metal oxide particles and the kind of organic solventused.

Examples of suitable organo-functionalised silicone polymers includedimethylpolysiloxysilazane, α-monohydroxysiloxane,α,ω-dihydroxypolydimethylsiloxane, α-monoalkoxypolydimethylsiloxane,α,ω-dihdroxypolydimethylsiloxane, α-dialkoxypolydimethylsiloxane,α-trialkoxypolydimethylsiloxane, α,ω-hexa-alkoxypolydimethylsiloxane,dimethylpolysiloxy chloride, dimethylpolysiloxy bromide, anddimethylpolysiloxy iodide. Preferred among those examples are.alpha.-monoalkoxypolydimethylsiloxane,.alpha.-dialkoxypolydimethylsiloxane,alpha.-trialkoxypolydimethylsiloxane, α-monohydroxymethylphenylsiloxane, α-trialkoxypolymethyl hexyl siloxane and methylstyryil/dimethyl polysiloxy bromide. They are adsorbed to the pigmentvery easily, and upon adsorption they impart a smooth feel to thetreated pigment. The reactive group in the organo-functionalisedsilicone may be joined to the silicon atom directly or indirectlythorough a substituent group.

Commercially available organo-functionalised silicone polymers which maybe employed to coat the metal oxide particles include the followingmaterials: X-24-9826, X-24-9171 and X-24-9174 manufactured by the ShinEtsu Co. Ltd; TSL 8185 and TSL 8186 manufactured by Toshiba Silicone Co.Ltd.; SIO6645.0 manufactured by Chisso Corporation; KBM-3103manufactured by Shin-Etsu Chemical Co. Ltd.; A-137 manufactured byNippon Unicar Co. Ltd.

In addition to providing the metal oxide particles with fibrils, theymay also be provided with a hydrophobic coating to improve theparticles' dispersion in hydrophobic carrier medium. The hydrophobiccoating may be applied as a pre-treatment, prior to provision of thefibrils, or as a post-treatment, after provision of the fibrils.Advantageously, the metal oxide particles comprise from 2 to 25%,preferably from 5% to 15%, more preferably from 7% to 12% hydrophobiccoating by weight of the metal oxide particles.

Advantageously, the hydrophobic coating may be made by applying amixture of one or more of the following materials and isopropyl alcoholonto the metal oxide powder and drying at 150° C. for 3 hours: reactiveorgano-polysiloxane, polyolefin (including polyethylene andpolypropylene), hydrogenated lecithin and salts thereof, N-acylaminoacid and salts thereof and dextrin fatty acid esters. Preferably, thereactive organo-polysiloxane comprises organo hydrogen polysiloxane,triorgano siloxy silicic acid and organopolysiloxane modified at bothterminal ends with trialkoxy groups. Commercially available materialsfalling into the category of reactive organo-polysiloxanes includeKF-99, KF-9901, KF-7312F, KF-7312-J, KF-7312K, KF-9001, KF-9002,X-21-5249 and X-21-5250 manufactured by the Shin-Etsu Chemical CompanyLtd; SH-1107, DC593, BY-11-015, BY-11-018 and BY-11-022 manufactured byDow Corning Toray Silicone Co. Ltd.; TSF484, TSF483 and TSF4600manufactured by Toshiba Silicone Co. Ltd.; FZ3704 and AZ6200manufactured by Nippon Unicar Co. Ltd.

The hydrophobic coating is not limited to those described in thepreceding paragraph and alternative hydrophobic coatings known to theskilled person may be employed instead. Such coatings may includetrialkoyl isopropyl titanate, preferably triisostearoyl isopropyltitanate and perfluoro coatings, preferably polyperfluoroethoxymethoxyPEG-2 phosphate.

Some coatings may both provide hydrophobic properties and exhibitfibrils to provide steric stabilisation to avoid flocculation.Commercially available coatings falling into this category includeKF9908 (Triethoxysilylethyl Polydimethylsiloxyethyl Dimethicone), KF9909(Triethoxysilylethyl Polydimethylsiloxyethyl Hexyl Dimethicone) andKP575 (Acrylate/Tridecyl Acrylate/TriethoxysilylproplylMethacrylate/Dimethicone Methacrylate Copolymer) from the Shin Etsu CoLtd.

Cosmetic compositions according to the invention comprise metal oxideparticles, which may comprise particles of any suitable metal oxide.Preferably, the metal oxide particles are selected from the groupconsisting of titanium oxide, zinc oxide, zirconium oxide, yellow ironoxide, black iron oxide, red iron oxide, chromium oxide, chromiumhydroxide, zirconium oxide and cerium oxide. More preferably, the metaloxide particles may be selected from titanium dioxide particles, zincoxide particles and mixtures thereof. More preferably still, the metaloxide particles comprise titanium dioxide particles.

As discussed above, the primary particle size is important indetermining the surface area of the secondary particles. Advantageously,the metal oxide particles according to the invention have a numberweighted average primary particle size from 10 to 500 nm, preferablyfrom 15 to 100 nm, more preferably from 20-65 nm, yet more preferablyfrom 25 to 40 nm. Within the defined ranges, secondary particles havinghigh surface areas and beneficial UV-B absorption properties may beformed.

As used herein, the term “primary particle size” means metal oxidecrystal size, as determined by x-ray diffraction. It is based onmeasuring the broadening of the strongest rutile line.

Furthermore, the metal oxide particles may have a number weightedaverage secondary particle size from 0.005 to 100 μm, preferably from0.015 to 10 μm, more preferably from 0.05 to 1 μm. Sunscreening metaloxides may advantageously have a number weighted average secondaryparticle size from 100 to 250 nm. Pigmentary metal oxides mayadvantageously have a number weighted average secondary particle sizefrom above 250 nm to 500 nm.

The number weighted average secondary particle size is determined usinga Nicomp 370 Sub Micron Particle Sizer.

Cosmetic compositions according to the invention may comprise from 0.1wt % to 45 wt % metal oxide particles. If metal oxide pigments arepresent, then the cosmetic composition preferably comprises from 0.05 wt% to 30 wt %, preferably from 1 wt % to 20 wt % metal oxide pigments. Ifmetal oxide sunscreen actives are present, then the cosmetic compositionpreferably comprises from 0.05 wt % to 15 wt %, preferably from 0.5 wt %to 10 wt %, more preferably from 1 wt % to 5 wt % metal oxide sunscreenactives.

Minute metal oxide particles have a highly reactive surface that cancause unwarranted chemical or photochemical reactions. To counter thiseffect, it is known to dope these surfaces with one or more othermaterials such as silica, or metal oxides, such as alumina, to reducethe reactivity of the surface. This surface treatment may typicallyrepresent from 15 to 30% by weight of the metal oxide particle.Advantageously metal oxide particles comprised within cosmeticcompositions according to the invention may be so-doped.

Commercially available sunscreens which may be employed in cosmeticcompositions according to the invention include KQ-1 from IshiharaCorp., M262 from Kemira Corp. and TTO S-3 and TTO S-4 from IshiharaCorp. Iron oxide pigments suitable for use herein include methiconetreated iron oxides available from Warner Jenkinson.

In a highly preferred embodiment, the following materials are employed:SAS/TTO S-3/D5 from Miyoshi Kasei which has an average primary particleof about 15 nm and SAI/NAI TR10 with a primary particle size of about100 nm. These commercially available materials are pre-coated withfibrils according to the invention.

Cross-linked organopolysiloxane elastomer may be present in an amountwhich is greater than 1.7% up to 15%, preferably from 2% to 10%, morepreferably from 2.2 to 5% by weight of the cosmetic composition. Asstated above, these are the amounts of solid organopolysiloxaneelastomer in the composition. Surprisingly, the present inventors haveestablished that above 1.7% elastomer, and especially in the preferredranges, the evenness of the benefit provided by the metal oxideparticles improves.

The compositions of the present invention may comprise emulsifyingcross-linked organopolysiloxane elastomer, non-emulsifying cross-linkedorganopolysiloxane elastomer or mixtures thereof. If present, then theemulsifying cross-linked organopolysiloxane elastomer is present in anamount from 0.01 to 15%, preferably from 0.01 to 1% by weight of thecomposition. In addition and if present, the non-emulsifyingcross-linked organopolysiloxane elastomer is advantageously present inan amount from 0.01 to 15%, preferably from 2-5% by weight of thecosmetic composition.

As used herein, the term “non-emulsifying”, when employed in relation tocross-linked organopolysiloxane elastomer includes cross-linkedorganopolysiloxane elastomer which comprise no polyoxyalkylene orpolyglyceryl units.

As used herein, the term “emulsifying” when employed in relation tocross-linked organopolysiloxane elastomer includes cross-linkedorganopolysiloxane elastomer which comprise at least one polyoxyalkylene(e.g., polyoxyethylene or polyoxypropylene) or polygyceryl unit.

No specific restriction exists as to the type of curableorganopolysiloxane composition that can serve as starting material forthe cross-linked organopolysiloxane elastomer. Examples in this respectare addition reaction-curing organopolysiloxane compositions which cureunder platinum metal catalysis by the addition reaction betweenSiH-containing diorganopolysiloxane and organopolysiloxane havingsilicon-bonded vinyl groups; condensation-curing organopolysiloxanecompositions which cure in the presence of an organotin compound by adehydrogenation reaction between hydroxyl-terminateddiorganopolysiloxane and SiH-containing diorganopolysiloxane;condensation-curing organopolysiloxane compositions which cure in thepresence of an organotin compound or a titanate ester, by a condensationreaction between an hydroxyl-terminated diorganopolysiloxane and ahydrolyzable organosilane (this condensation reaction is exemplified bydehydration, alcohol-liberating, oxime-liberating, amine-liberating,amide-liberating, carboxyl-liberating, and ketone-liberating reactions);peroxide-curing organopolysiloxane compositions which thermally cure inthe presence of an organoperoxide catalyst; and organopolysiloxanecompositions which are cured by high-energy radiation, such as bygamma-rays, ultraviolet radiation, or electron beams.

Preferred non-emulsifying organopolysiloxane compositions aredimethicone/vinyl dimethicone crosspolymers. Such dimethicone/vinyldimethicone crosspolymers are supplied by a variety of suppliersincluding Dow Corning (DC 9040, DC 9041), General Electric (SFE 839 andVelvesil materials), Shin Etsu (KSG-15, 16, 18 [dimethicone/phenyl vinyldimethicone crosspolymer]), Grant Industries (Gransil(™) line ofmaterials), lauryl dimethicone/vinyl dimethicone crosspolymers suppliedby Shin Etsu (e.g., KSG-31, KSG-32, KSG-41, KSG-42, KSG-43, and KSG-44).

Particularly useful emulsifying elastomers are polyoxyalkylene-modifiedelastomers formed from divinyl compounds, particularly siloxane polymerswith at least two free vinyl groups, reacting with Si—H linkages on apolysiloxane backbone. Preferably, the elastomers are dimethylpolysiloxanes cross-linked by Si—H sites on a molecularly spherical MQresin. Examples of commercially available emulsifying cross-linkedorganopolysiloxane elastomers include KSG-21 (comprising 27% solidorganopolysiloxane elastomer) and KSG-210 (comprising 24% solidorganopolysiloxane elastomer) and KSG-320 from the Shin-Etsu ChemicalCompany Ltd. Commercially available examples of emulsifying cross-linkedorganopolysiloxane elastomers comprising polyglyceryl units are KSG 710and KSG-800 from the Shin-Etsu Chemical Company Ltd.

Advantageously, cosmetic compositions according to the inventioncomprise an oil. Oil may be present in an amount from 7% to 80% byweight of the cosmetic composition.

The oil may be selected from the group consisting of volatile oils,non-volatile oils and mixtures thereof.

As used herein, the term “non-volatile” when employed in relation to anoil includes oils that fulfil at least one of the following definitions:(a) the oil exhibits a vapour pressure of no more than about 0.2 mm Hgat 25° C. and one atmosphere pressure; (b) the oil has a boiling pointat one atmosphere of at least about 300° C.

As used herein, the term “volatile” when employed in relation to oilsincludes materials that are not “non-volatile” as previously definedherein.

Any non-volatile oil adhering to the above definition may be included incosmetic compositions according to the invention. Such non-volatile oilsmay include silicone oils, both functionalised and non-functionalised,hydrocarbon oils and mixtures thereof. Non-volatile oil may be presentin an amount from 0 to 20%, preferably from 1 to 10% by weight of thecosmetic composition.

Volatile oils which may be included in cosmetic compositions accordingto the invention may include silicone oils, both functionalised andnon-functionalised, hydrocarbon oils and mixtures thereof. Volatile oiluseful in the present invention may exhibit one or more of the followingcharacteristics—it may be saturated or unsaturated, have a straight orbranched chain or a cyclic structure.

Examples of volatile hydrocarbons which may be incorporated intocosmetic compositions according to the invention include polydecanessuch as isododecane and isodecane (e.g., Permethyl-99A which isavailable from Presperse Inc.) and the C₇-C₁₅ isoparaffins (such as theIsopar Series available from Exxon Chemicals).

Examples of volatile silicone oils which may be incorporated intocosmetic compositions according to the invention include cyclic volatilesilicones corresponding to the formula:

wherein n is from about 3 to about 7 and linear volatile siliconescorresponding to the formula:(CH₃)₃Si—O—[Si(CH₃)₂—O]_(m)—Si(CH₃)₃wherein m is from about 1 to about 20 preferably from 3 to 12.

Preferably, the cyclic volatile silicone is cyclopentasiloxane orcyclohexasiloxane.

Linear volatile silicones generally have a viscosity of less than about5 centistokes at 25° C.; cyclic silicones generally have viscosities ofless than about 10 centistokes at 25° C.

Examples of commercially available volatile silicone oils include thefollowing cyclomethicones: Dow Corning 200, Dow Corning 244, Dow Corning245, Dow Corning 344, and Dow Corning 345 (commercially available fromDow Corning Corp.); SF-1204 and SF-1202 Silicone Fluids (commerciallyavailable from G. E. Silicones), GE 7207 and 7158 (commerciallyavailable from General Electric Co.); and SWS-03314 (commerciallyavailable from SWS Silicones Corp.). Other examples of commerciallyavailable methyl silsesquioxanes available as TMF 1.5 fluid fromShin-Etsu Chemical Co; SILCARE SILICONES, for example phenyl substitutedsilsesquioxanes available as Silcare 15M60, n-Octyl substitutedsilsesquioxanes available as Silcare 31M60 and 31M50, hexyl methicone,caprylyl methicone and lauryl methicone available as Silcare 41M10,41M15 and 41M20 respectively from Clariant.

Volatile oil may be present in an amount from 7 to 70%, preferably from10% to 50%, more preferably 20% to 40% by weight of the cosmeticcomposition.

In one advantageous embodiment, it is preferred that the volatile oilcomprise a mixture of volatile cyclic silicone and volatile lineardimethicone of viscosity from 2 to 50×10⁻⁶ m²/s (2-50 cst), morepreferably from 3 to 50×10⁻⁶ m²/s (3-5 cst), more preferably still from3 to 50×10⁻⁶ m²/s (4 cst). Without wishing to be bound by theory it isbelieved that, during dry-down the linear dimethicone may remain on theskin longer to keep the metal oxide particles wetted, thereby reducingagglomeration. Agglomeration is responsible for colour drift, in thecase of pigments, and reduced SPF efficacy, in the case of sunscreens.

Advantageously, the ratio of volatile cyclic silicone to volatile lineardimethicone is from 1:1 to 25:1, preferably from 5:1 to 10:1.

Preferred examples of linear dimethicones useful include DC200 5 cst,DC1630 and DC5-2117, more preferably, the linear dimethicone comprisesDC5-2117.

Cosmetic compositions according to the invention may be formulated asanhydrous products or as emulsions. If the cosmetic compositions areformulated as emulsions, those emulsions may be water-in-oil(water-in-silicone) emulsions or oil-in-water (silicone-in-water)emulsions, but are preferably water-in silicone emulsions.

Advantageously, the cosmetic compositions according to the invention areformulated as water-in-silicone emulsions that contain from 0.1 to 70%,preferably from 1 to 50%, more preferably from 5 to 40% water.

Cosmetic compositions according to the invention, whether or not theyare in the form of an emulsion, may comprise emulsifier. The emulsifiermay be selected from the group consisting of nonionic, anionic,cationic, zwitterionic and amphoteric emulsifiers and mixtures thereof.Suitable emulsifiers are disclosed in McCutcheon's Detergents andEmulsifiers, North American Edition, pages 317-324.

In the event that the cosmetic composition according to the invention isa water-in-silicone emulsion, then preferred emulsifiers are selectedfrom the group consisting of polyoxyalkylene copolymers (also known assilicone polyethers), polyglyceryl copolymers and mixtures thereof.Polyoxyalkylene copolymers are described in detail in U.S. Pat. No.4,268,499. More preferred polyethers include PEG/PPG-18/18 Dimethiconeavailable as blend with cyclopentasiloxane as DC5225C or DC5185; PEG 9Dimethicone, available as KF6017 or KF6028 from Shin-Etsu. A preferredpolyglyceryl emulsifier is available as KF6100 and KF6104 from Shin-EtsuInc.

In one embodiment, it is preferred that cosmetic compositions accordingto the invention comprise only polyglyceryl copolymer emulsifiers and nopolyoxyalkylene emulsifiers. This is because polyoxyalkylene emulsifiersmay break down to release ethylene glycol and aldehydes which may giverise to increased sensitivity on the skin of some consumers.

The total concentration of the emulsifier may be from 0.01% to about15%, more preferably from about 0.1% to about 10% of the formulation,even more preferably from 1.0% to about 5% and more preferably stillfrom about 1.0% to about 3%, by weight of the composition.

Cosmetic compositions according to the present invention may optionallycontain spherical particles having an average particle diameter from 1to 50 μm, preferably from 5 to 20 μm. As used herein in relation to thespherical particles, the particle diameter shall be understood to bethat of primary particles.

Preferred spherical particles include, but are not limited, to polymericparticles chosen from the methylsilsesquioxane resin microspheres suchas for example those sold by GE silicone under the name Tospearl 145A orTospearl 2000; microspheres of polymethylmethacrylates such as thosesold by Seppic under the name Micropearl M 100; the spherical particlesof crosslinked polydimethylsiloxanes, especially such as those sold byDow Corning Toray Silicone under the name Trefil E 506C or Trefil E505C, sphericle particles of polyamide and more specifically Nylon 12,especially such as those sold by Atochem under the name Orgasol 2002DNat Cos, polystyerene microspheres such as for example those sold byDyno Particles under the name Dynospheres, ethylene acrylate copolymersold by Kobo under the name FloBead EA209 and mixtures thereof. Alsofound to be useful is Ronasphere LDP from Kobo Inc. Polyurethaneparticles BPD500 sold by Kobo Inc. may also be employed.

If present, the spherical particles may be included in the cosmeticcompositions according to the invention at a concentration of from about0.01% to about 40%, more preferably from about 1% to about 10%, morepreferably still from about 1% to about 5%.

Cosmetic compositions according to the present invention may furthercomprise a skin-conditioning agent. These agents may be selected fromhumectants, exfoliants or emollients and may be present from about 0.01%to 30%, preferably from about 1% to about 20%, more preferably fromabout 1% to 10% by weight of the cosmetic composition.

Humectants which may be included in cosmetic compositions according tothe invention include polyhydric alcohols such as glycerine, propyleneglycol, dipropylene glycol, polypropylene glycol, polyethylene glycol,sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol,1,2,6-hexanetriol, ethoxylated glycerin, propoxylated glycerine andmixtures thereof. Most preferably the humectant comprises glycerine.

In addition, hydrophilic gelling agents such as those selected from thegroup consisting of the acrylic acid/ethyl acrylate copolymers,carboxyvinyl polymers (such as those sold by the B.F. Goodrich Companyunder the Carbopol trademark, polyacrylamides (such as those availablefrom Seppic as Seppigel 305) and mixtures thereof may be included in thecosmetic compositions according to the invention.

Cosmetic compositions according to the present invention mayadditionally comprise an organic sunscreen. Suitable sunscreens may haveUVA absorbing properties, UVB absorbing properties or a mixture thereof.The exact amount of the sunscreen active will vary depending upon thedesired Sun Protection Factor, i.e., the “SPF” of the composition aswell as the desired level of UVA protection. The compositions of thepresent invention preferably comprise an SPF of at least 10, preferablyat least 15. SPF is a commonly used measure of photoprotection of asunscreen against erythema. The SPF is defined as a ratio of theultraviolet energy required to produce minimal erythema on protectedskin to that required to products the same minimal erythema onunprotected skin in the same individual (see Federal Register, 43, No166, pp. 38206-38269, Aug. 25, 1978).

Cosmetic compositions according to the present invention may comprisefrom about 2% to about 20%, preferably from about 4% to about 14%, byweight, of organic sunscreen. Suitable sunscreens include, but are notlimited to, those found in the CTFA International Cosmetic IngredientDictionary and Handbook, 7^(th) edition, volume 2 pp. 1672, edited byWenninger and McEwen (The Cosmetic, Toiletry, and Fragrance Association,Inc., Washington, D.C., 1997).

A variety of additional optional ingredients may be incorporated intothe compositions of the present invention. Non-limiting examples ofthese additional ingredients include additional skin care actives suchas peptides (e.g., Matrixyl [pentapetide derivative]), farnesol,bisabolol, phytantriol, urea, guanidine (e.g., amino guanidine);vitamins and derivatives thereof such ascorbic acid, vitamin A (e.g.,retinoid derivatives such as retinyl palmitate or retinyl proprionate),vitamin E (e.g., tocopherol acetate), vitamin B₃ (e.g., niacinamide) andvitamin B₅ (e.g., panthenol) and the like and mixtures thereof;anti-acne medicaments (resorcinol, salicylic acid, and the like;antioxidants (e.g., phytosterols, lipoic acid); flavonoids (e.g.,isoflavones, phytoestrogens); skin soothing and healing agents such asaloe vera extract, allantoin and the like; chelators and sequestrants;and agents suitable for aesthetic purposes such as essential oils,fragrances, skin sensates, opacifiers, aromatic compounds (e.g., cloveoil, menthol, camphor, eucalyptus oil, and eugenol).

EXAMPLES

The following examples further describe and demonstrate the preferredembodiments within the scope of the present invention. The examples aregiven solely for the purpose of illustration, and are not to beconstrued as limitations of the present invention since many variationsthereof are possible without departing from its scope.

A liquid foundation of the present invention is prepared as follows: ina suitable vessel, water, glycerine, disodium EDTA and benzyl alcoholare added and mixed using conventional technology until a clear waterphase is achieved. When the water phase is clear, the methylparabens areadded and mixed again until clear. The resultant phase is mixed with aSilverson SL2T or similar equipment on high speed (8,000 rpm, standardhead). In a separate vessel, the KSG21, DC245, Pigment dispersion, otheroils and the parabens are added and the mixture is milled using aSilverson SL2T on a high speed setting until a homogeneous mixture iscreated.

Following this step, the water phase and the silicone phase are combinedand milled using the Silverson SL2T on a high speed setting until thewater is fully incorporated and an emulsion is formed. The elastomer isthen added and the mixture is mixed again using the Silverson on a highspeed setting to generate the final product.

Example # Ingredient 1 2 3 4 5 DC9040 cross linked 25.00 20.00 30.00elastomer gel¹ KSG15 cross linked 20.00 50.00 elastomer gel² Dimethiconecopolyol 5.00 10.00 0.5 cross-polymer (KSG21)³ Cyclomethicone (DC245)10.00 5.00 3.00 28.00 10.0 PEG/PPG18/18 1.8 2.0 2.2 Dimethicone &Cyclomethicone (DC5185) Octyl Methoxy cinnamate 4.00 2.00 Octacrylene4.00 Diethylhexyl carbonate 4.00 2.00 (Tegosoft DEC) 4cst Dimethicone(DC5- 4.00 1.9 2117) Fibril coated sunscreen 6.0 6.00 6.00 gradeTitanium dioxide 50% dispersion SAS/TTO-S-3/D5 Fibril coated pigmentary4.00 8.00 grade Titanium dioxide 80% dispersion SA/NAI-TR-10/D5 Fibrilcoated pigment 0.2 0.1 50% dispersion SA/NAI-B-10/D5 Fibril coatedsunscreen 8.00 grade Titanium dioxide 40% dispersion M262 coated with15% KP9909 Titanium dioxide 9.00 2.00 10.00 10.00 Iron oxides 1.50 1.501.50 2.00 1.50 Propylparabens 0.1 0.1 0.1 0.10 Ethylparabens 0.1 0.1 0.10.20 Methylparabens 0.1 0.1 0.1 0.10 Disodium EDTA 0.1 0.1 0.1 0.01Benzyl alcohol 0.5 0.5 0.5 0.25 Sodium chloride 2.00 2.00 2.00 Glycerin10.00 12.00 7.00 Niacinamide 2.00 5.00 5.00 0.50 Water qs qs qs Nil qs¹DC9040 comprises 11% solid organopolysiloxane elastomer incyclopentasiloxane. ²KSG15 comprises 9% solid organopolysiloxaneelastomer in cyclopentasiloxane. ³KSG21 comprises 27% solidorganopolysiloxane elastomer in cyclopentasiloxane.

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention. To the extent that any meaning ordefinition of a term in this written document conflicts with any meaningor definition of the term in a document incorporated by reference, themeaning or definition assigned to the term in this written documentshall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modification can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. A cosmetic composition comprising: (a) metal oxide particles having acoating of organo-functionalised silicone fibrils that are bonded to andextend away from the surface of the metal oxide particles; and (b)greater than about 1.7% by weight of the cosmetic composition of across-linked organopolysiloxane elastomer, wherein the fibrils areattached by treating the metal oxide particles with anorgano-functionalised silicone polymer comprising a reactive moietyselected from the group consisting of amino, imino, halogen, hydroxyl,and alkoxyl, and wherein the fibril-coated metal oxide particles arecoated with a hydrophobic coating.
 2. The cosmetic composition of claim1, wherein the organo-functionalised silicone polymer comprises fromabout 5 to about 100 silicone units.
 3. The cosmetic composition ofclaim 1, wherein the organo-functionalised silicone polymer has a ratio(Mw/Mn) of weight-average molecular weight (Mw) to number-averagemolecular weight (Mn) from about 1.0 to about 1.3.
 4. The cosmeticcomposition of claim 1, wherein the organo-functionalised silicone is alinear organo-functionalised silicone.
 5. The cosmetic composition ofclaim 4, wherein the reactive moiety is located at one end of themolecular chain of the linear organo-functionalised silicone.
 6. Thecosmetic composition of claim 1, wherein the organo-functionalisedsilicone is a branched chain organo-functionalised silicone.
 7. Thecosmetic composition of claim 6, wherein the reactive moiety is locatedon a side chain.
 8. The cosmetic composition of claim 7, wherein theside chain on which the reactive moiety is found is located within fivesilicone repeating units of one end of the silicone backbone.
 9. Thecosmetic composition of claim 1, wherein the metal oxide particles havea number weighted average secondary particle size from about 0.001 μm toabout 100 μm.
 10. The cosmetic composition of claim 9, wherein the metaloxide particles have a number weighted average secondary particle sizefrom about 0.015 μm to about 10 μm.
 11. The cosmetic composition ofclaim 10, wherein the metal oxide particles have a number weightedaverage secondary particle size from about 0.05 μm to about 1 μm. 12.The cosmetic composition of claim 1, wherein the metal oxide particleshave a number weighted average primary particle size from about 10 μm toabout 500 nm.
 13. The cosmetic composition of claim 12, wherein themetal oxide particles have a number weighted average primary particlesize from about 15 μm to about 100 nm.
 14. The cosmetic composition ofclaim 13, wherein the metal oxide particles have a number weightedaverage primary particle size from about 20 μm to about 65 nm.
 15. Thecosmetic composition of claim 1, wherein the metal oxide particles areselected from the group consisting of titanium dioxide, zinc oxide,cerium oxide, zirconium oxide, iron oxide particles and mixturesthereof.
 16. The cosmetic composition of claim 1, wherein thehydrophobic coating is manufactured by treating the surface of the metaloxide particles with a material selected from the group consisting of areactive organo-polysiloxane, a polyolefin, a hydrogenated lecithin, asalt of hydrogenated lecithin, an N-acylamino acid, a salt ofN-acylamino acid, a dextrin fatty acid ester, and mixtures thereof. 17.The cosmetic composition of claim 16, wherein the reactiveorgano-polysiloxane is selected from the group consisting of an organohydrogen polysiloxane, a triorgano siloxy silicic acid, anorganopolysiloxane modified at both terminal ends with trialkoxy groups,and mixtures thereof.
 18. The cosmetic composition of claim 1,comprising from above about 1.7% to about 15% by weight of the cosmeticcomposition of cross-linked organopolysiloxane elastomer.
 19. Thecosmetic composition of claim 18, comprising from about 2% to about 10%by weight of the cosmetic composition of cross-linked organopolysiloxaneelastomer.
 20. The cosmetic composition of claim 19, comprising fromabout 2.2% to about 5% by weight of the cosmetic composition ofcross-linked organopolysiloxane elastomer.
 21. The cosmetic compositionof claim 1, comprising from about 0.01% to about 15%, by weight of thecosmetic composition of emulsifying cross-linked organopolysiloxaneelastomer.
 22. The cosmetic composition of claim 21, comprising fromabout 0.01% to about 1% by weight of the cosmetic composition ofemulsifying cross-linked organopolysiloxane elastomer.
 23. The cosmeticcomposition of claim 1, comprising from about 0.01% to about 15% byweight of the cosmetic composition of non-emulsifying cross-linkedorganopolysiloxane elastomer.
 24. The cosmetic composition of claim 23,comprising from about 2% to about 5% by weight of the cosmeticcomposition of non-emulsifying cross-linked organopolysiloxaneelastomer.
 25. The cosmetic composition of claim 1, additionallycomprising from about 7% to about 80% by weight of the cosmeticcomposition of oil.
 26. The cosmetic composition of claim 25, whereinthe oil is selected from the group consisting of volatile oil,non-volatile oil and mixtures thereof.
 27. The cosmetic composition ofclaim 26, wherein the volatile oil is selected from the group consistingof volatile cyclic silicone oil, volatile linear dimethicone having aviscosity from 2 to 50×10⁻⁶ m²/s (2-50 cst) and mixtures thereof. 28.The cosmetic composition of claim 27, wherein the ratio of volatilecyclic silicone oil to volatile linear dimethicone is from about 1:1 toabout 25:1.
 29. The cosmetic composition of claim 28, wherein the ratioof volatile cyclic silicone oil to volatile linear dimethicone is fromabout 5:1 to about 10:1.
 30. The cosmetic composition of claim 1,additionally comprising an emulsifier.
 31. The cosmetic composition ofclaim 30, wherein the emulsifier is selected from the group consistingof polyoxyalkylene copolymers, polyglyceryl copolymers and mixturesthereof.
 32. The cosmetic composition of claim 30, wherein theemulsifier is free of a polyoxyalkylene emulsifier.
 33. The cosmeticcomposition of claim 1 additionally comprising an organic sunscreen. 34.The cosmetic composition of claim 1, additionally comprising sphericalpolymeric particles having an average particle diameter from about 1 μmto about 50 μm.
 35. The cosmetic foundation composition comprising acosmetic composition according to claim
 1. 36. A cosmetic compositioncomprising: (a) metal oxide particles having a coating oforgano-functionalised silicone fibrils that are bonded to and extendaway from the surface of the metal oxide particles and having a numberweighted average primary particle size from about 15 nm to about 100 nm;and (b) greater than about 2% by weight of the cosmetic composition ofcross-linked non-emulsifying organopolysiloxane elastomer, wherein thefibrils are attached by treating the metal oxide particles with anorgano-functionalised silicone polymer comprising a reactive moietyselected from the group consisting of amino, imino, halogen, hydroxyl,and alkoxyl, and wherein the fibril-coated metal oxide particles arecoated with a hydrophobic coating.